HVAC Techs Can't Diagnose Over-Amping on Site
HVAC professionals are facing challenges including condenser failures due to storms, difficulty diagnosing over-amping issues, and a lack of understanding regarding centrifugal pumps. Many express frustration with complex systems and seek guidance on troubleshooting.
SOURCES (39)
“I try posting a pic and sharing a imgur link but my post failed. Where my furnace combines with the HVAC ducts, I feel air around it when my ac unit is running. Is it a normal thing or any cons to it? Thanks? https://imgur.com/a/PkrmDW8…”
“Hi All, I have a Lennox CX35-49c-6f-20 air handler with a 3.5ton condenser. Long story short, the condensate pump failed. Of course when they installed it they also ran the drain from another unit in our attic into the same pump and that kept producing water as it ran because nothing is wired to tell it to stop running. This caused it to overflow and almost fully submerge the wet switch for this unit. I disconnected the pump from power and the unit and capped both wires individually going to the”
“Hello all, Moved into new, to us, house in the spring. Have been having some AC issues and the tech has found a condenser leak. Looks like I’m going to need to replace. He mentioned the current unit seems to be undersized. Location: greater Toronto area, Ontario, Canada Current unit size: 3 ton House layout: 2 story detached with a finished basement. Brick built in the late 80s with insulation. Lots of windows Square footage: 3650 above grade and about 1800 finished in the basement Entire house”
“Context here, our unit evap coil is leaking and we are basically totally empty on refrigerant. Unit is 10 years old. Called my local guy who did our furnace replacement and was the cheapest option when we did that. And as you can see lowest end option is 8900 and a repair plus refrigerant is 3700. Our unit needs about 10lbs of 410a and across the different companies it’s about 300 dollars per lb. As i understand 410a is going up in price since production of it it’s going down. Don’t really know”
“I just realized I've never changed the filter on this HVAC system (it has been 8 years). I can't find the owner's manual online. Where does the filter go, and why is the manual so hard to find? I was thinking the filter went into this door-looking thing with the red Honeywell emblem (2nd pic), but it didn't seem to open. submitted by /u/hedgehog_face [link] [comments]”
“Looking for input / help. One of our contacts had some AC replacements done back in 2020 on their rental units. One of the issues was Can any of you make out what is going on with that flue pipe or what your theory is? Feel free to input on any other issues you notice with the work too! submitted by /u/TechnicalApproval [link] [comments]”
“I have a Beckett CB201 condensation pump on my AC. The barb on the check valve where the hose attaches had cracked and was leaking water. I can't get a replacement check valve locally, I have to order it, and it will take a few days to arrive. But I live in Phoenix, I need my AC ... a LOT! I took the check valve to Home Depot (it is the black plastic piece in the photos, the end with white tape is where it threads into the pump). The 1/4" threading below where the barb cracked is still”
“Seeing if I can have some comparisons here… One of our AC units (2.5 ton) compressor went out today and we were quoted by Goettl around 6k for a replacement compressor and then 9,600 for a whole replacement unit outside. We can’t get quotes from any other company because they ‘need to come diagnose’ 😒 Has anyone recently had their units replaced? Are we being robbed? submitted by /u/Adorable-Pack-1778 [link] [comments]”
“Can't make this stuff up. Goodman totally wired the new system wrong. I got it all installed and then realized that there was no kill switch ( and no wires). so, it won't run because it thinks the front cover is off. Ok, i can fix that; hot wire LINE H to the 120v line coming in and order a new switch. but wait, they sent LINE H somewhere into the bowels of a harness mess. so if i pull the LINE H off to configure properly, who knows what will break. help! submitted by /u/mpg2”
“I need tu replace this unit. I was given a quote on a Carrier a/c system (condenser and air handler- not sure if this is the name). Can y'all share your pricing for a similar a/c the pictures attached? how much you charge to install? Thanks. submitted by /u/Ramys0624 [link] [comments]”
“Homeowner said the compressor would not turn. For the life of me I could not imagine why. /s submitted by /u/Advanced-Educator-55 [link] [comments]”
“This is a rely set in a hydronic HVAC at a hotel I know it's completely wrong but what are anybody's comments submitted by /u/Beginning-Chance-881 [link] [comments]”
“ac co just installed and massive vent temp differences on small to big. submitted by /u/Material_Cry_8293 [link] [comments]”
“This one is a doozy. I had a technician come out and increase my subcooling from 5.2 to 9.6. He mentioned that the second tech dispatched to my home completely missed this issue, though I don't know why. The unit was installed in July 2025. The house feels warm on hot days. The tech was out last Friday and said the unit is working properly. I saw the pressures on his guage and the subcooling was overing over a 9.5/9.6, but the ambient temperature was only in the high 70s to low 80s. He is re”
“When the tech was still testing the running of the heatpump, I saw some white on the outside of the lineset. But after he finished I don't see any frost. It is cold but not as cold. A little bit of the line set (about one inch) at the outdoor condensor unit is exposed (without insulation). Is this normal or should it be a bit frosted there? I think the air coming out should be a bit cooler. He has to still return next week. Midea mo1se-h36b-2a Apparently he wired it as 24v and I only see Y1”
“Good day and dealing with somethjng that may have been going on for a while unnoticed. Make and model of the 6 to 7 years old unit in title. AC was finally given a break the last day or two in New England [after multi day heat wave] and noticed the fan still running in background after shut off at the thermostat. Trying the DIY, at least in gathering information, as I have a pretty good level of interest in learning as well as ability and tools. Right now I have the safety shut off flipped to pr”
“Been getting HVAC replacement quotes. And one person did a pretty thorough job and checked my boiler too. I have a closed loop boiler system into air handlers that uses forced air heat for first and second floors. But baseboard heating for basement. It’s a Williamson and 23 years old. Attaching pictures. The HVAC tech told me that the boiler expansion tank was full of water and will need to be replaced. He also noted the PSI was at 31-32 and temps still at 115-120F even in the summer with no hea”
“Found the system overcharged with a suction of 150lbs Corrected the charge but now it’s not cooling at all. submitted by /u/Any_Performer_1566 [link] [comments]”
“I'm going to try to keep this message as brief as possible but will be supplying a lot of detail about a Carrier furnace, its installation, and an ongoing overheating that led to its premature failure. Ultimately, I am trying to determine if installation manual is incorrect. And, if there is any recourse for (what I believe to be) an error in installation documentation provided by Carrier. I'm also trying to understand why no HVAC technician noted the incorrect installation over the year”
“Is a 1.9k estimate for leak check / Seal./ Evac and refill a 6,1 lb 410a dual zone split air reasonable? submitted by /u/HelpfulSandwich8029 [link] [comments]”
“My neighbor asked me for my opinion on why his central AC unit tripped out his entire house at 4am. There were no other major loads running at that time. The compressor is about 5years old and appears to he in good condition. I did not open the unit...because it was raining and I'm not an hvac guy and like any good primadonna "not my job". The house main is 125A..compressor on a 40a. There was evidence of water in the air handler and PCB/control board had some minor corrosion. His”
“Just had the compressor, condensor, and expansion valve in my 2014 Sierra replaced for what feels like an overpriced $3k. It's blowing cold but doesnt seem as cold as I expected. I live in central FL so its quite hot and humid. At 92° outside it struggled to get down to the mid/high 60s, even after 30 minutes of driving on recirc. For comparison I got in my Corvette (also a 2014 6.2L) and it got down to 38 degrees after just a couple of minutes (same day, same time). I drove the Corvette the”
“Should have taken a pic before the HVAC guy came for a consultation because I'm not sure he put the wires back correctly. I decided to pull it off and take a look. If I'm reading the diagram correctly the RED wire goes to HERM, the YELLOW goes to COMMON and the blue (WHITE) goes to FAN. But the YELLOW and the blue (WHITE) are both connected to the COMMON terminal. I called them out because outdoor fan won't spin and cold air stopped coming out of the vents. No freezing, condensation”
“Worked on a 15 year old Ruud condenser with a 20 year old Goodman coil. Condenser was dirty as hell with 400+ high side pressure at somewhere around 90 ambient and 80 indoor. 8 subcool and 35 superheat. Delta T was 15 Cleaned it and took new readings. Head pressure went down to 330 initially before climbing towards 400 again. Subcool stayed steady at 8-9. Superheat fluctuated from 0 to 40. New Delta T of only like 12. Is this a hunting TXV? Open TXV? With an obercharge? Are there non condensible”
“Hi everyone, I have a Mitsubishi Electric multi-split system (4 indoor units connected to 1 outdoor unit) with 4 SFA mini condensate pumps . I’m not sure of the exact pump model. I’m considering replacing them with the Refco VAMP-F (3004238) because the SFA pumps are quite noticeable, especially at night. My indoor units are: 3 × Mitsubishi Electric AY25VGK 1 × Mitsubishi Electric AY50VGK Does anyone here have any real-world experience with the Refco VAMP-F? How quiet is it compared to other min”
“Hey folks, this morning my old AC unit decided not to turn on and run. Everything in the house is operating as normal, the outside unit just isn't running. I did a little bit of trouble shooting including testing the fuses with a multimeter and I believe the 25 amp fuse in the picture is blown. My question is should I replace these fuses with FRN or time delay 30 amp fuses? Is that an ok thing to do? Or should I be looking for some other fuse type. Is there a reason two different fuses are i”
“Active 2.0 needs 4.8gpm minimum going into the machine. You don’t have enough flow. You also need steel braided hose can’t tell if you do or not from the video. This is the reason why I went with the Ryobi. I could only get 4.6gpm from my tap. I really wanted the Active.”
“I’m going to flush it, but the system doesn’t call for any glycol or inhibitors. Anyone have recommendations for any good gentle cleaners for chill water with copper nickel and aluminum? And despite the system not calling for inhibitors, would you guys run some anyway? Continually flushing and adding new water seems like asking for hardness build up. submitted by /u/nyuckajay [link] [comments]”
“The storm brought EF-1 tornado level winds, the news said. I had two service calls Sunday (on call) with condensers blown completely off the pads. Nothing like resetting condensers by yourself... submitted by /u/MasterPhilip [link] [comments]”
“A coworker couldn't figure out why the unit was over-amping. Smh. submitted by /u/Ok_Animator_8461 [link] [comments]”
“Anyone know of some good books about pumps/closed loop systems? I have Pumping Away by Holohan, looking for something a little more sciency. Pumps are definitely my weakest point and what i scratch my head the most on. submitted by /u/IHateYork [link] [comments]”
“Getting leakage from the An area of duct that’s causing condensation to form into the metal emergency pan. Any tips on insulating the hard to reach spots? Can’t get around to the other side there’s framing and what not. Someone needs was saying spray foam since I can’t reach my hand back there. Any suggestions would be greatly appreciated. submitted by /u/ContributionKnown473 [link] [comments]”
“Still under warranty but I'm just gonna put a service Tee and a screw on pressure switch on there, is there any good arguments against this? The customer will still pay much less than if you recover and braze one in, plus there system has been opened. idk im Just curious because this is what I would do to my own unit if I had to choose. submitted by /u/mdmitchell301 [link] [comments]”
“Yeah, but for some reason, we just set the condensers on the pump ups and call it a day. It's sop over here.”
“Dang. We strap all units to the wall for code but I was always skeptical of the winds ability to actually topple a big unit like this Saving this to show customers why we do it.”